code: def make_model_name(model_dir):
      """
      Make the model checkpoint folder.
      the checkpoint file will be located at `model_dir/models/` folder,
      the filename will start with FILE_PREFIX.
  
      :param model_dir: niftynet model folder
      :return: a partial name of a checkpoint file `model_dir/model/FILE_PREFIX`
      """
      _model_dir = touch_folder(os.path.join(model_dir, "models"))
      return os.path.join(_model_dir, FILE_PREFIX)
  
file_path: NiftyNet/niftynet/engine/handler_model.py
imports: import os
  import tensorflow
  from niftynet.engine.application_variables import global_vars_init_or_restore
  from niftynet.engine.signal import ITER_FINISHED, SESS_FINISHED, SESS_STARTED
  from niftynet.io.misc_io import touch_folder
label_desc: Use image node_id 1 for calling a global function with example usage: make_model_name(model_dir) and returns: os